There are numerous trends notable within the breakdown of Conservative MPs backing either Leave or Remain in the EU referendum – from the divide between the frontbench and the backbenches, to the geographical patterns and the generational divide. One which no-one seems to have picked up on yet is the split among ethnic minority Tory MPs.

The majority of ethnic minority members – nine of the 17 – have backed Leave, with six supporting Remain. Two – Rehman Chishti and Seema Kennedy – are still undeclared on the topic. I’ve listed them all below, and annotated the members of the 2015 intake, who have broken 5-1 for Leave, an even more pronounced margin.

One MP suggested to me that a possible factor behind the figures is that ethnic minority MPs are by background more inclined to take a more global – rather than eurocentric – view. All are proudly British, but all also have good reason to look beyond the relatively parochial EU when they consider the world and our country’s place in it. Nadhim Zahawi’s positive case for a Britain which “can change itself and change the world” is just one example of this. Nus Ghani, another Leaver, argued in her maiden speech that “this country is at its best when it is open to the world”.

It may be a coincidence, but it is of course the case that various other prominent Eurosceptics have personal stories which link them to the world beyond the EU – such as Dan Hannan, who spent his childhood in Peru, and Douglas Carswell, who grew up in Uganda. While some on the other side choose to sneer about “little Englanders”, these facts suggest that’s a nonsense.

This breakdown among MPs points to a referendum battleground which hasn’t been explored much in the early stages of the referendum campaign, but which could play a major part in the result. While the pro-EU campaign are trying to work out ways to play on the fears of those whose friends or family members are EU citizens resident in the UK, there is a possible opportunity for the Leave campaign to make a very specific pitch to those voters whose family background is non-EU.

One theme highlighted by Leave campaigners which will form part of that pitch is the perception of a deep unfairness in immigration policy, as non-EU migrants are treated increasingly strictly in an attempt to counter-balance the free movement of EU citizens. Saqib Bhatti, the joint secretary-general of the newly-formed Vote Leave group Muslims for Britain, wrote about it in yesterday’s Yorkshire Post:

“…we are a global country, linked by migration to every part of the world. If you are from a Commonwealth background, you will almost certainly know people who have had difficulty bringing friends and relatives to the UK – not to settle, but simply to visit. The UK has had to crack down savagely in its visa regime for non-EU nationals to make unlimited space for people with no connections to Britain. How can we have got to the position where we effectively turn away computer programmers from Bangalore in order to admit unskilled workers from Brasov?

I’m not arguing for an open-door immigration policy vis-à-vis the Commonwealth, any more than we should have one vis-à-vis the EU. All I’m asking for is fairness.”

This won’t be the last we hear of this and other messages specifically targeted to ethnic minority voters.